Outside of the High Technology chapter, it's hard to say if this was really a deliberate policy.

Stealth is additive, because presumably it's a coating; configuring the hull, and messing around with it's relative density looks very much multiplicative.

As long as they look reasonable, and in proportion with other costs associated with shipbuilding, within the game they don't matter, as long as they are within reach of the player characters.

As regards to militarized vacuumed rocks, their primary appeal was the the addition of their natural armour class to create super armoured protection, above the technological limitations, otherwise you'd rather use that twenty or thirty five percent to pack in more weapon systems.

I fool around with designing these space potatoes to game the best bang for buck, whether commercially or militarily, and by removing the super protection capability, you have to come up with other rational to use them.

That's why I mentioned that when you need five percent to get two armour factors, seven and a half percent per one plus five percent overhead look more attractive.

The astrogator know the relationship of the spaceship to the universe, and the relationship of the universe to the spaceship; not necessarily the same thing.

He is responsible for figuring out the desired departure point of the starship from the warp, and the optimal point of entry and angle to the warp to reach the desired departure point, and the spacetime length of the jump.

In today's dollars, a cubic metre of concrete weighs in at about hundred bucks; my calculation puts that at twenty credit imperiale.

The difference between pouring concrete, and the usual ways of building a hull, is that volume doesn't count except in the sense of ascertaining how much of it will be enclosed; in other words, and in simplified form, two hundred tonnes in volume could be enclosed would be the equivalent of twenty by twenty by twenty deckplan spaces.

Let's say that a tad less than a one and a half metre thick wall of concrete is enough to take the strain of acceleration, so that's twenty times twenty times six, plus twenty times twelve, plus eight, totalling 4808 spaces.

That equals one hundred twenty point two tonnes. or 37.53903810118676% wastage.

Of course, this is very dependant on the structural strength of concrete, and if one and half metres is enough, the larger a spaceship gets, the less you'd need in porportion to volume, therefore less wastage.

The hull armour table shows how much of the hull’s tonnage is consumed per point of armour protection added, along with its costs. A minimum technological level is required for each type of armour, and there is a maximum amount that can be attached to a hull – this includes any armour the ship had prior to modification.

This has been discussed before, but let me point out again that the cost of armourplating is based on the base cost of the hull, which means planetoid variants are peanuts comparatively, by as much as a factor of ten, or possibly more with denser hulls, divided by eighty percent.

To figure out the default volume to base hardpoints on, for planetoids you have three possible options:

1. Volume is volume, so total tonnage counts.

2. Wastage can't be utilized, so only usable volume counts for hardpoints.

3. Or, like armourplating, that protective layer counts as part of the usable volume, just permanently tied to natural armour class, and only five percent is truly counted as wastage; in other words, for a planetoid and the buffered variant, ninety five percent of the volume counts as the default volme to ascertain hardpoints.

It's implied that some form of miniaturized repulsion beams are embedded in the hull of appropriately equipped spaceships.

Considering that a Tigress would have to calculate the optimum compensation for thousands of individual crew members, it seems more likely that it's a projected anti gravity field that nullifies the gravitational force created by acceleration, projected in the forward direction of that acceleration.

It's implied that some form of miniaturized repulsion beams are embedded in the hull of appropriately equipped spaceships.

Where is this implied?

All canon has to say on the matter is that there are three completely magical technologies with no explanation whatsoever of how they work. Grav plates, acceleration compensation and then the totally magic heat sinks which are necessity but not even mentioned.

Consider - you have a 6g/9g/25g (take your pick what the limit is) and yet inside the ship the crew experiences a 1g force that is usually perpendicular to the engine thrust, and they are unaffected by violent maneuvers because the acceleration compensation cancels them.

Nested force fields - a gravitic drive, an artificial gravity field and an acceleration compensation field. I would even go as far as to suggest that gravitics could include some sort of waste heat disposal system to complete the set. You cut down on the handwavium if you postulate that the maneuver drive, artificial gravity, acceleration compensation and heat management are all variations on the same basic magi-tech rather than have to three/four separate suspensions of disbelief.

Even the jump drive is described as being discovered during research into maneuver drives and thus can be wrapped into the one magi-tech:

The asteroid belt station became the key to the future quite
by accident. Exploitation of the asteroids required economical
and efficient drives that would enable large quantities of ore to
be moved about. The lab produced the thrusters that were called
for, but it also discovered the jump drive (in 2087); the zero-G
environment of the asteroid belt was exactly what was required
before the space-rending effects of jump drive could be even
seen.

Sigtrygg wrote: ↑
All canon has to say on the matter is that there are three completely magical technologies with no explanation whatsoever of how they work. Grav plates, acceleration compensation and then the totally magic heat sinks which are necessity but not even mentioned.

Acceleration compensation is explicitly grav plates:

HG'80, p17 wrote:Tech level requirements for maneuver drives are imposed to cover the grav plates integral to most ship decks, and which allow high-G maneuvers while interior G-fields remain normal.

Gravity: Most ships have grav plates built into the deck flooring. These plates
provide a constant artificial gravity field of 1G. Acceleration compensators are alsousually installed, to negate the effects of high acceleration and lateral G forces
while maneuvering. A ship's passengers would be unable to tell whether they were
moving through space or grounded on a planet without looking out a viewscreen.

Acceleration compensation is an addition to the grav plates - a related technology as I have postulated but still an add on.

You can have grav plates with no compensation, you can have grav plates with the acceleration compensation 'option'.

Sigtrygg wrote: ↑
Nope, its explicitely an addition to the grav plates:

Does not follow from your quote.

The HG quote explicitly states that grav plates negates the effects of acceleration.

The S7 quote says that acceleration compensation is an optional system, even when grav plates are installed.

According to canon grav plates can push or pull (up or down), not effectively drag sideways. To provide acceleration compensation we would need grav plates that can vary the g-field quickly, and often provide force perpendicular to the deck which would probably require grav plates perpendicular to the deck, i.e. in the bulkheads.

What I'm trying to say is that acceleration compensation probably require a more complex system than straight downward gravity, so can be optional even if it based on the same technology.

We can even have a half-way system that can negate constant acceleration, but not violent manoeuvres, such as combat:

Gravity: The ship's decks have plates built in to provide constant gravity; these may be adjusted to provide any G value between 0 and 1G. Computer instructions are needed to revise or switch off plate values. Under normal conditions acceleration dampers negate the effects of acceleration or deceleration, but in situations where violent manoeuvring is expected, such as combat, these are switched off to prevent overload, and the crew must rely on other measures such as acceleration couches.

The S7 quote clearly states that acceleration compensation is an addition to grav plates therefore grav plates by themselves offer no acceleration compensation.

Alternatively I could quote from about half a dozen CT sources that separate grav plates and acceleration/inertial compensators. The fluff text for the Gazelle in JTAS 4:

Gravitics: Inertial compensators; 1G floor field

Or the write up of the Kinunir in A1:

Gravity: The ship decks have grav plates built-in to provide a constant 1G floor
field. These plates may be turned off only through computer instructions. In
addition, the ship itself is under the influence of acceleration dampers which negate
the effects of acceleration while maneuvering.

How about this from The Traveller Adventure:

Gravity: Deck flooring includes integral grav plates which
provide a constant 1 -G artificial gravity field. Acceleration
compensators are also installed and negate the effects of
high acceleration and lateral G forces while maneuvering.

The HG quote is an oversimplification or an alternative rule, HG does considerably change the ship technology paradigm from CT:1-3 - fancy CT having different rules in different books...

Sigtrygg wrote: ↑
The S7 quote clearly states that acceleration compensation is an addition to grav plates therefore grav plates by themselves offer no acceleration compensation.

Yes, it has two systems installed artificial gravity and acceleration compensation; both can very well be based on grav plates (and HG explicitly says so).

Sigtrygg wrote: ↑
Alternatively I could quote from about half a dozen CT sources that separate grav plates and acceleration/inertial compensators. The fluff text for the Gazelle in JTAS 4:

Gravitics: Inertial compensators; 1G floor field

So the compensators are a gravitic system?

Gravitic items are those devices which utilize the principles of antigravity, ...

Sigtrygg wrote: ↑
So I agree, gravitics is going to include grav plates, and acceleration compensation, and the technologies are probably very similar. hence my suggestion of nested fields.

So we basically agree?

Then I misunderstood you when you said:

Sigtrygg wrote: ↑
All canon has to say on the matter is that there are three completely magical technologies with no explanation whatsoever of how they work. Grav plates, acceleration compensation and then the totally magic heat sinks which are necessity but not even mentioned.

I would certainly agree that artificial gravity and acceleration compensation is quite magical (in the Clark sense) and it's completely undefined how it works.

Yet the manoeuvre drive does not set up a gravity field to accelerate the ship, at least not one that extends to the interior of the ship, else we would not need any acceleration compensation. If the entire ship was affected by the same gravity field the ship and it's occupants would accelerate at the same rate and no force or dislocation would be experienced by the crew; essentially the crew would experience free fall as the ship accelerated (just like when a spacecraft in orbit is accelerated by the planet's gravity field).

Or it could be three separate systems with synergistic properties. ( Two mechanisms though)

M-drive using a repellent (Anti-gravity) force for propulsion, grav plates throughout the hull generating gravity along a constant plane through the vessel and again from the m-drive and through the grav plates an inertial damper. ( Think of it as more of a heat sink for inertia.)